This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. This is an observational study looking at the natural history of West Nile virus [WNV] infection. The investigators are trying to better understand how the West Nile Virus [WNV] affects people.